When tuning instruments having a keyboard, particularly pipe organs, it is necessary to selectively activate the keys while tuning the instrument at a location which is further than arm's reach from the keyboard. In the past, and indeed even to this day, it is common for those who tune pipe organs to employ an assistant to activate the keys on command from the organ tuner, who then tunes the pipes as necessary to adjust for changes in tuning brought about by physical deterioration of the organ or changes in the seasons, which also affect the tuning and necessitate retuning to compensate.
Obviously, in these days of high inflation, the use of an assistant means that the organ tuner must charge for the services of an assistant who merely depresses the keys. If the services of the assistant could be eliminated, then productivity would be increased, the fee for tuning could be reduced, and the tuner could even improve his profit margins.